It is interesting how DEC migrated from a "all known, all standard" system
on UNIBUS and QBUS where any register address and bit was known
to a wide varying family of machines where things are new all the time.

It was *never* the same. At the level of the kernel, VAX-11/780 UNIBUS
is different from VAX-11/750 UNIBUS, which is different from VAX-11/730
UNIBUS.
--
roger ivie
rivie%ridgenet.net@localhost